How do you keep a single object from casting a shadow?
Objects not casting shadows? easy, un-tick the shadow box.


In Cycles 2.79+, Ray Visibility was renamed to Cycles Settings.

As for the lighting, Cycles simulates the physical behaviour of light with some reasonable accuracy. All techniques used in real photography can be applied to lighting setups in cycles, The video also discusses the composite of various render passes, I think you'll find they are all possible in Blender. Be specific about what you want to know and you will get accurate answers.